Denture liners

ABSTRACT

A process for preparing hydrophilic cross-linked polymers and products prepared thereby, said process comprising admixing in a solvent-free system in the presence of a free radical, vinyl polymerization catalyst and reacting a major amount of a water-soluble polymerizable monoester of an olefinic acid having at least one substituted functional group with a minor amount of a polymerizable diester of one of said olefinic acids having at least two esterifiable hydroxyl groups. The novel products include a solid friable foam which can be disintegrated to powder. Shaped bodies can be prepared in the form of articles which can be cast with or without additives such as fragrances, medicinals, flavors, chemicals and the like, which are gradually released from the article when it is wetted in water or alcohol. Liquid casting syrups adapted to be polymerized in situ with or without additives can be formed and can be used for example in preparing denture liners. The casting syrups can be prepared in water to yield a polymer soluble in alcohol which is suitable for formation of hydrophilic coatings as by spray, dip, casting and the like.

United States Patent @lhce 3,618,213 Patented Nov. 9, 1971 Int. Cl. A61c13/00 U.S. Cl. 32-2 3 Claims ABSTRACT OF THE DISCLOSURE A process forpreparing hydrophilic cross-linked polymers and products preparedthereby, said process comprising admixing in a solvent-free system inthe presence of a free radical, vinyl polymerization catalyst andreacting a major amount of a water-soluble polymerizable monoester of anolefinic acid having at least one substituted functional group with aminor amount of a polymerizable diester of one of said olefinic acidshaving at least two esterifiable hydroxyl groups. The novel productsinclude a solid friable foam which can be disintegrated to powder.Shaped bodies can be prepared in the form of articles which can be castwith or without additives such as fragrances, medicinals, flavors,chemicals and the like, which are gradually released from the articlewhen it is wetted in water or alcohol. Liquid casting syrups adapted tobe polymerized in situ with or without additives can be formed and canbe used for example in preparing denture liners. The casting syrups canbe prepared in water to yield a polymer soluble in alcohol which issuitable for formation of hydrophilic coatings as by spray, dip, castingand the like.

This application is a continuation-in-part of applications Ser. No.567,856, filed July 26, 1966 and Ser. No. 650,259, filed June 30, 1967,and is a division of application Ser. No. 654,044, filed July 5, 1967.

This invention relates to novel hydrophilic polymers and processes ofmaking same and has particular relation to such hydrophilic polymers inthe form of casting syrups, friable solid foams and in powdered form,the latter form being particularly adapted as a carrier formedicinally-active substances and for natural and synthetic flavors,essences, fragrances, spices, food colors, sweeteners, dyes and thelike.

It is known to produce hydrophilic polymers, particularly to producecross-linked hydrophilic polymers and, more particularly, to producesame in the form of shaped body hydrogels in an aqueous solution bycopolymerization whereby a major portion of a monoester ofacrylic ormethacrylic acid with a bi-functional alcohol which has an esterifiablehydroxyl group and at least one additional hydrophilic functional groupis copolymerized in aqueous solution with a small amount of a diester ofthese acids and of an alcohol which has at least two esterifiablehydroxyl groups (see U.S. Pat. Nos. 2,976,576 and 3,220,960).

It is known that said prior art shaped body, hydrophillio polymersprepared in an aqueous system are carriers for medicinally-activesubstances. Thus, it is known that medicinally-active substances may bedissolved in the aqueous constituent of such prior art shaped bodyhydrogels to provide gradual release of the medicinally-activesubstances, however, the resulting solutions are diflicult to handle andstore and the medicinal components are susceptible to air oxidation,degradation, deterioration, evaporation, etc.

Heretofore, it has been necessary toprepare a solid or shaped body ofthe hydrophilic polymer and thereafter dissolve in the aqueousconstituents of such shaped body the medicinal flavor, sweeteners,coloring agent and the like. Additionally, in the prior art preparation,employing copolymerization in an aqueous solution, it has not beenpossible to directly prepare a foam by the addition of the usual foamingagents, such as sodium bicarbonate, for the reason that a softsemi-gelatinous hydrogel product resulted rather than the desired hardfriable foam and it was not possible to convert such semi-gelatinousprodnot to a friable foam or to a compactable powder.

In addition, the said prior art process employing the conventional redoxcatalyst such as sodium bicarbonate and ammonium persulfate, potassiumsulfate, sodium thiosulfate and ammonium persulfate or potassiumsulfate, caused the polymerization reaction to go to completion attemperatures above 0 C. thereby preventing the preparation of aprepolymer preferably in the form of a liquid casting syrup which iscapable of being dyed, pigmented, thickened and otherwise varied in formand thereafter cured to form solid or shaped bodies such as rods,sheets, tubes and other molded articles, or a hard, friable foam as willbe hereinafter further described.

Additionally, said prior art process has resulted in an incompletely (upto about 95%) polymerized polymer and has further resulted in a polymercapable of absorbing excess amounts (more than 30% and up to by weight)when fully equilibrated in aqueous solutions.

The novel hydrophilic polymers of the present invention prepared in awater-free state, are substantially completely (about 99.5%) polymerizedand are incapable of absorbing more than up to about 30% by weight ofwater when equilibrated in aqueous solution.

It now has been found that hydrophilic polymers can be prepared in awater-free system so as to permit the direct preparation of liquidcasting syrups in prepolymer form which can be used for direct in situpolymerization in the form of castings of shaped bodies, films andcoatings, which can be treated with conventional foaming agents such assodium bicarbonate to result in hard, friable foams which can bedirectly formed into the swelled state or ground directly to powderform.

It also has been found that hydrophilic polymers can be prepared in awater-free system so as to permit ready preparation of the hydrophilicpolymer products in powdered form. An object of the present invention isto prepare said hydrophilic polymers in a water-free system to permittheir direct conversion to a powdered foam whereby the powdered polymersare especially adapted as carriers for medicinally-active substances,natural or synthetic flavors, essences, fragrances, spices and the like.The polymeric powders of the present invention have been found to becompact in form and have been found to provide the necessary stabilityand shelf life to enable their use as carriers for medicinal andflavoring substances which are susceptible to chemical reactions such asair oxidation, deterioration, evaporation and degradation.

A further advantage derived from the compactness ability of the instantpowdered hydrophilic polymers is that upon encapsulation of the saidpowder carrying medicinally-active substances, flavors, essences and thelike, greater stability and longer shelf life are provided than washeretofore possible.

Polymeric powders containing encapsulated flavors, essences or spicescan be reconstituted in solution at will, thus providing superiorflavoring solution because encapsulation prevents air deterioration ofthe flavoring component and also prevents losses due to evaporation.

The liquid casting syrups of this invention are prepared by mixing amajor amount of suitably purified commercial polymerizable monoester ofan olefinic acid containing at least one substituted hydrophilicfunctional group with a minor concentration of a free-radical catalystand heating from ambient temperature to 80 C. until the polymerizedportion of the monomer no longer shows water solubility. This product isthen cooled to room temperature and addition of theoretical catalystcontent carried out. The casting syrup can then be suitably dyed andpigmented and the fluid viscosity increased as desired by addition ofappropriate thickening agents.

The casting syrup can then be cured to form products capable of beingcast, formed or machined into rods, sheets, etc., for various uses. Theproduct can exist in a rigid state, swelled state or as a foam. Thepolymer obtained from the cured casting liquids has good mechanicalstrength, reversible fluid absorption properties, the ability to retainits shape in a fluid media and to elastically recover it afterdeformation.

The casting syrup is also suitable, for example, for in situpolymerization in dental prosthesis, particularly for use in thepreparation of denture liners and mouth guards. The absorbent qualitiesof the cured product permit advantageous use in other medical-surgicalapplications such as heart valves, vessel substitutes, dializerdiaphragms, intrauterine devices and the like.

Prior to the addition of dyes, pigments, thickening agents, or otheradditive components, the liquid casting syrups are added to an excessquantity of water to form a precipitated polymer. The latter is solublein highly polar organic solvents such as alcohols, glycols and glycolethers. The precipitated polymer, when dissolved in polar solvents, isused as a polymer solution for the formation of films, coatings and thelike. Alternately, the precipitated polymer is dried and used forfabrication of shaped articles, by casting, injection molding,extrusion, calendaring and the like.

In a further embodiment of the invention, hydrophilic solublethermoplastic polymers are prepared by suspension polymerization ofhydroxy ethyl methacrylate in a non-polar medium such as silicone oil ormineral oil. The monomer containing catalyst is dispersed in thenonpolymer medium in the form of small droplets which polymerize to formfinely divided spheres or beads. Such beads may be dissolved in polarorganic solvents for the preparation of films, coatings and the like.Also, the beads may be used directly in the fabrication of thermoplasticshaped articles as by injection molding, extrusion, calendaring and thelike. Suspension polymerization, preferably, is conducted in an oil bathat temperatures ranging from 50l50 C. until bead formation is completed.The ratio of suspension oil to monomer preferably is from about :1 toabout 20:1. The catalyst to monomer ratios preferably rang from about0.05 to 1.0 per 100 parts monomer.

The hydrophilic polymers of the present invention, polymerized in thewater-free state, can be formed to adhere to metal, glass, rubber,plastics and other surfaces. Also, they can be cast into solid bodieswhich can be formed and ground into toric contact lens, which heretoforehas not been possible with hydrophilic polymers polymerized in aqueoussolution.

Starting materials which may be utilized in accordance with the presentinvention are hydroxy alkyl esters of an alpha-beta unsaturatedcarboxylic acid such as 2-hydroxy ethyl methacrylate, hydroxy propylmethacrylate and the like. These are admixed in a water-free system withappropriate quantities of a free radical catalyst such as tertiary butylperoctoate, isopropyl percarbonate, benzoyl peroxide, and the like and asuitable cross-linking monomer such as ethylene glycol dimethacrylate,1,3- butylene dimethacrylate, 1,4-butylene dimcthacrylate or otherpolyfunctional monomeric esters.

Free radical catalyst concentrations in the range of 0.05 g. to l g.catalyst per 100 g. of polymerizable hydroxy alkyl ester have been foundto be adequate with 4 the preferred quantity being between 0.1 and 0.2per 100 g. starting material.

The mechanical properties imparted to the polymer of the invention andits ability to retain water as a homogeneous constituent are stronglyinfluenced by the proportion of poly-functional cross-linking agentpresent. For the polymer of this invention, concentrations of 0.05 to 15g./ 100 g. of 2-hydroxy ethyl methacrylate have been found convenient,the preferred range being 0.1 to 0.2 g. cross-linking agent per 100 g.of polymerizable hydroxy alkyl ester.

Polymerization of the above reactants may be accelerated by theapplication of heat or, by selecting the catalyst and the amountthereof, the application of heat may be omitted and rapid polymerizationinduced at ambient temperatures. In instances where heat is applied forcuring, temperatures ranging from about 20 C. to about 150 C. have beenfound to be convenient with 40 to 70 C. being the preferred range.

Another object of the present invention is to produce new properties, asset forth above, and to improve and upgrade existing properties of thebase hydrophilic polymer material by the incorporation therewith of aminor amount of one or more additive components selected from the groupconsisting of resins, rosin esters, phenoxy resins, silicone resins, lowmolecular weight polyisobutylenes, synthetic polymers and prolamines.The new compositions are especially adapted to form polyblends, whichproduce new properties and improve and upgrade existing properties ofthe base hydrophilic polymer.

The mixture is heated or otherwise cured in the absence of compatiblevolatile or non-volatile organic solvents to produce thermosettingpolymeric materials having properties superior to those of the majorconstituent of the formulation. The upgrade properties of these newcompositions of matter include, but are not necessarily limited to,improved hardness, adhesion, abrasion resistance, resiliency, andtoughness. The polymerized material will yield products with improvedmachining and polishing characteristics and may also find use as amolding powder or polyblended with other molding compounds. Other slightproperty improvements can be effected through use of small amounts ofother cross-linking glycol dimethacrylate.

The method of this invention may be used to produce thermosettingsurface coatings with improved adhesion to various substrates or toproduce thermosetting resins for use as sheetings and films withimproved clarity and toughness.

In general, Z-hydroxy ethyl methacrylate and the crossl nking monomerethylene glycol dimethacrylate in quantities ranging from 10 to 50% byweight (preferred range of 50%) is mixed with -50% by weight of acommercral ly available resin of the coumarone indene type or theirphenol modified counterparts in the presence of a free radical catalystsuch as tertiary butyl peroctoate, isopropyl percarbonate, etc., andheated at temperatures ranging from 40 to 200 C. for approximately 30minutes. Organic or inorganic solvents are used as necessary to increasecompatibility of the components. Compatible polymers having improvedproperties of tensile strength, modulus, hardness, thermal conductivity,etc., are formed. The foregoing preferred proportional limitations alsoare employed with the phenoxy resin and the silicone resin additivecomponents.

The resulting polymers can be prepared in the form of films or rodssuitable for grinding into fine powders. By admixing foaming agents suchas sodium bicarbonate with the reactants prior to curing, the polymermay be obtained in the form of a foam which is easily distintegratedinto a fine powder by means of a shearing action. The polymeric powdersof this invention are preferably obtained from foams. Quantities of 1 to10 grams foaming agent per grams of reactants have been found to besufficient.

Polymeric powders prepared by any of the above means are mixed withnatural or synthetic flavors or essences dissolved in an appropriatesolvent and the mixture placed on a mechanical roller so that thesolution becomes intimately mixed. The solution is then filtered anddried by air evaporation or forced heat. Upon evaporation of the solventthe flavoring or essence is retained by the powder. Due to its extremehydrophilicity and because the hydrophilic polymer of this invention hasreversible fluid adsorption properties, the powders can be reconstitutedin solution at will to provide solutions which give concentrated flavorsor essences.

Vessel substitutes for humans made from plastics are well known inthemselves but when made from the polymers of the invention possess newand useful properties. In addition to the required properties such aschemical, physical and thermal inertness, vessel substitutes made fromthe polymers of the invention possess unusual colloidal properties whichpermit them to be very closely assimilated to those of living tissue andhence suitable for contact with body tissues for prolonged periods oftime. Articles made from the polymers of the invention can be sterilizedby boiling and, by steeping them in a physiological solution prior toinsertion as a body tissue replacement, can be made isotonic with thesurrounding tissue.

An unexpected advantage of articles made from the polymers of theinvention is that because of their reversible fluid adsorptionproperties, heparin, dissolved in isotonic salt solution, or otheranticoagulants in a suitable solvents, can be added during manufactureand polymerization in situ can then be effected. The anticoagulant isthen present in the vessel substitute for slow release after transplantto prevent thrombic formation. Medicinally-active substances, such asantibiotics and other active substances such as bacteriocides,antivira'ls, fungicides, which are water or alcohol soluble, may beadded prior to polymerization or the end product polymer may be immersedin a solution of such substances to form a carner.

The mechanical properties imparted to the polymer of the invention andits ability to achieve isotonicity with the surrounding tissue arestrongly influenced by the proportion of polyfunctional cross-linkingagent present. For the polymers of this invention, concentrations of0.05 to g./ 100 g. of 2-hydroxy ethyl or hydroxy propyl methacrylatehave been found to be convenient, the preferred range being 0.1 to 1.0g. cross-linking agent per 100 g. of polymeriza'ble hydroxy alkyl ester.

Prior to casting, the vessel substitutes may be reinforced withstrenghtening materials such as woven glass fibers, Dacron and the like,in various mil and denier sizes present in tubular form in the mold sothat the strengthening material is completely encased by the castingsolution.

Polymerization of the casting solutions may be accelerated by theapplication of heat or, by selecting the catalyst and the amountthereof, the application of heat may be omitted and rapid polymerizationinduced at ambient temperatures. lIn instances where heat is applied forcuring temperatures broadly ranging from about 150 C. are used withranges from about 20- 100 C. being found convenient, the preferred rangebeing about 40-80 C. The reaction preferably is performed in an inert oranaerobic atmosphere employing carbon dioxide or nitrogen. It is knownthat the presence of oxygen inhibits the polymerization reaction thusrequiring a longer reaction time or the use of increased polymerizingtemperatures.

Additionally, the polymers of the present invention are particularlyadapted for the manufacture of other prosthetic devices such as bodyimplants inasmuch as the liquid casting syrups in prepolymer form can beused for direct in situ polymerization. Contraceptive devices, such asintrauterine implants, diaphragms, and the like are well known in theart. A difliculty commonly encountered in the fabrication of suchdevices is that the material from which they are made is frequentlyirritating to such body tissues as mucous membranes. In addition, thesedevices frequently undergo deterioration on repeated sterilization byboiling water or steam. The difliculties encountered in the prior artmay be eliminated by fabrication of contraceptive devices comprised ofthe polymers of the present invention.

In addition to the required properties such as chemical, physical andthermal inertness, the contraceptive devices made from the polymers ofthis invention possess unusual colloidal properties which permit them tobe closely assimilated to living tissue. This permits them to besuitable for contact for prolonged periods of time. In order to obtain adevice of suitable rigidity in such instances where this property isdesired, it is preferable to blend in a filler material with the castingresin prior to final cure. The filler material may be an inert salt,such as barium sulfate, calcium carbonate, clay and the like. Anothermeans of constructing a tissue compatible contraceptive device is bycoating such a device made from another rigid plastic with the polymercomposition of the present invention. Such a rigid device may beconstructed of nylon, polyethylene, and the like. The poly-hydroxyalkylester functions to make the device more compatible with the tissue.

A further use of the present hydrophilic polymers in particulate formsuch as powders, beads, extrusions and the like, is as a filter mediumfor tobacco smoke and other gaseous combustion products. The presenthydrophilic polymer provides a non-migratory humectant carrier when itis presaturated in a polyhydric alcohol, e.g., glycerine propyleneglycol, polypropylene glycol and ethylene glycol. Additionally, thehydrophilic polymers of the present invention provide an excellentindustrial filter medium in that they have the ability to retain andrelease other components, such as thiourea or dithioaerythritol, whichare stable against oxidation and are therefore available for reactionwith the toxic, irritant or odorous combustion products of the exhaustsmoke to eliminate or modify same to non-objectionable form. Suchcomponents need only be soluble in the polyhydric alcohol, alcohol orwater which is carried by the hydrophilic filtering medium. Thus,adsorption of and reaction with nitrous oxides, hydrocarbons and othercombustion products in the gas stream can be had.

The hydrophilic filtering medium additionally can be compounded withtobacco flavoring material to fortify or supplement the flavor lost inthe train of exhaust tobacco smoke on inhalation through the presentfilter medium which is capable of removing some of the tars andnitrogenous combustion products which are understood to contribute thedesired tobacco flavor. Additionally, specific flavoring materials suchas menthol and the like also can be incorporated into the filtermaterial for release into the smoke train so as to improve the taste ofthe tobacco smoke upon inhalation.

The hydrophilic filter medium of the present invention can be readilyemployed for use as a chromatographic filter by means of its ability toabsorb water soluble pigmented stain or color components.

In another embodiment of the invention the present hydrophilic polymersin powdered form also may be employed as a thickening agent in foods,particularly in view of their ability to take up water when in the drystate.

In still another embodiment of the invention, the hydrophilic gelmaterials of the present invention may be employed in the form of acovering or bandage carrying medication which can be slowly releasedfrom the hydrophilic gel material. Preferably, the bandage is formed ofa plastic mesh reinforcement member carrying the hydrophilic gelmaterial in the form of a strip or layer which has been cast thereon.

In still another form of the invention, the hydrophilic gel material isadapted to carry water-soluble nutrients which can be released undercontrolled conditions. Thus, agar plates can be formed to carry thewater soluble nutrient, then dried and available for substantiallyinstant use upon soaking in water.

These and other objects and embodiments of the invention will be readilyunderstood by reference to the following examples which are given by wayof illustration without limitation:

Example 1 Purified Z-hydroxy ethyl methacrylate is stirred with across-linking monomer, ethylene glycol dimethacrylate, in theconcentration of 0.15 gram per 100 grams 2-hydroxy ethyl methacrylate.To the mixture is added 90 percent by weight of styrene copolymer resin(a commercial brand resin Piccoflex was employed) and 0.15 gram of afree-radical, vinyl polymerization catalyst, isopropyl percarbonate, inan anaerobic atmosphere at ambient temperature. The solution is castinto a mold to form a shaped diaphragm which is cured for thirty minutesat 200 C. for approximately 30 minutes and removed from the mold. Thediaphragm is machined and polished to form a finished article.

Example 2 Purified 2-hydroxy ethyl methacrylate is stirred with ethyleneglycol dimethacrylate, in the concentration of 0.1 gram per 100 grams2-hydroxy ethyl methacrylate. To the mixture is added 50 percent byweight of coumaroneindene resin (a commercial brand resin Cumar wasemployed) and 0.15 gram isopropyl percarbonate is added in an anaerobicatmosphere at ambient temperature. The solution is cast onto a steelpanel in the form of a film which is cured for 30 minutes at 40 C. toform a thermosetting film characterized by high gloss, adhesion,abrasion resistance, hardness and high impact strength.

Example 3 Purified 2-hydroxy ethyl methacrylate is stirred with ethyleneglycol dimethacrylate, in the concentration of 0.1 gram per 100 grams2-hydroxy ethyl methacrylate. To the mixture is added 75 percent byweight of polyvinyl acetate resin (a commercial brand resin Polyco wasemployed) and 0.15 gram benzoyl peroxide is added in an anaerobicatmosphere at ambient temperature. The solution is cast onto a steelpanel to form a film which is cured for 30 minutes at 100 C. to form athermosetting film characterized by high gloss, adhesion, abrasionresistance, hardness and high impact strength.

Example 4 Purified Z-hydroxy ethyl methacrylate is stirred with ethyleneglycol dimethacrylate, in the concentration of 0.05 gram per 100 grams2-hydroxy ethyl methacrylate. To the mixture is added 50 percent byweight of terpene resin (a commercial brand resin Piccolyte wasemployed) and 0.05 gram isopropyl percarbonate is added in an anaerobicatmosphere at ambient temperature. The solution is cast onto a steelpanel to form a film which is cured for 30 minutes at 40 C. to form athermosetting film characterized by high gloss, adhesion, abrasionresistance, hardness and high impact strength.

Example 5 Purified 2-hydroxy ethyl methacrylate is stirred with ethyleneglycol dimethacrylate, in the concentration of 0.3 gram per 100 grams2-hydroxy ethyl methacrylate. To the mixture is added 50 percent byweight of phenolic resin (a commercial brand resin Durez was employed)and 0.3 gram isopropyl percarbonate is added in an anaerobic atmosphereat ambient temperature. The solution is cast onto a steel panel to forma film which is cured for 30 minutes at 40 C. to form a thermosettingfilm characterized by high gloss, adhesion, abrasion resistance,hardness and high impact strength.

Example 6 Purified 2-hydroxy ethyl methacrylate is stirred with ethyleneglycol dimethacrylate, in the concentration of 1.0 gram per gramsZ-hydroxy ethyl methacrylate. To the mixture is added 50 percent byweight of pentaerythritol ester of a rosin derived resin (a commercialbrand resin Pentalyn A was employed) and 0.2 gram isopropyl percarbonateis added in an anaerobic atmosphere at ambient temperature. The solutionis cast onto a steel panel to form a thermosetting film which is curedfor 30 minutes at 40 C. to form a film characterized by high gloss,adhesion, abrasion resistance, hardness and high impact strength.

Example 7a Purified 2-hydroxy ethyl methacrylate is stirred withethylene glycol dimethacrylate in the concentration of 0.1 gram per 100grams Z-hydroxy ethyl methacrylate. To the mixture is added 50 percentby weight of glycol ester of a rosin resin (a commercial brand resinPolypale Ester was employed) and 0.15 gram isopropyl percarbonate isadded in an anaerobic atmosphere at ambient temperature. The solution iscast onto a steel panel to form a film which is cured for 30 minutes at40 C. to form a thermosetting film characterized by high gloss,adhesion, abrasion resistance, hardness and high impact strength.

Example 7b The foregoing process is repeated with a methyl ester of arosin resin (a commercial brand resin Abalyn being employed to replacethe resin of the previous example) to result in a thermosetting film.

Example 7c The foregoing process of Example 7a is repeated with ahydroabietyl alcohol (a commercial brand of a balsamic liquid Abitolbeing employed to replace the resin of Example 7a) to result in athermosetting film.

Example 7d The foregoing process of Example 7a repeated withpolycaprolactam (a commercial brand Nylon-6 was employed to replace theresin of Example 7a) to result in a thermosetting film.

Example 7e The foregoing process of Example 7a is repeated withpolysiloxane (a commercial brand resin GE silicone Resin 84 beingemployed to replace the resin of Example 7a) to result in a shaped bodyin the form of a decorative article.

Example 8a Purified 2-hydroxy ethyl methacrylate is stirred withethylene glycol dimethacrylate, in the concentration of 0.1 gram per 100grams 2-hydroxy ethyl methacrylate. To the mixture is added 50 percentby weight of phenoxy resin characterized as a high molecular polyhydroxyether resin prepared from bisphenol A and epichlorohydrin resin (acommercial brand resin Phenoxy 8500 was employed) and 0.15 gramisopropyl percarbonate is added in an anaerobic atmosphere at ambienttemperature. The solution is cast onto a steel panel to form a filmwhich is cured for 30 minutes at 40 C. to form a thermosetting filmcharacterized by high gloss, adhesion, abrasion resistance, hardness andhigh impact strength.

Example 8b The foregoing process is repeated with low molecular weightpolyisobutylene in the range of 8700 to 10,000 M.W. (a commercial brandresin Vistanex LM-MS being employed to replace the polyhydroxy etherresin of the foregoing example) to form a thermosetting filmcharacterized by high gloss, adhesion, abrasion resistance, hardness andhigh impact strength.

Example 8c The foregoing process of Example 8a is repeated with analcohol soluble protein of corn consisting of globular prolamine havinga molecular weight range of 40,000- 50,000 (a commercial brand resinZein being employed to replace the polyisobutylene of the foregoingExample 8a) to form a thermosetting film characterized by high gloss,adhesion, abrasion resistance, hardness and high impact strength.

Example 98.

Z-hydroxy ethyl methacrylate (100 parts) is combined with t-butylperoctoate (0.05 part) at 25 C. in an inert amtosphere. This mixture iscombined with Nylon-6 (100 parts) in trifiuoroethanol (850 parts) toform a clear solution. This is heated at 65 to 70 C. to form aprepolymer. The prepolymer solution is cooled to 25 C. and t-butylperoctoate (0.10 part) and ethylene glycol dimethacrylate (0.2 part) isadded. The viscous syrup is passed through an extruder having an orificeof 0.01 in diameter. The extruded fiber is passed immediately into aheated water bath, maintained at a polymerizing temperature of 80 C.After 30 minutes the solid fiber is removed from the water is air driedand oriented at 100 C.

Fabrics made from this fiber are extremely smooth in texture and have ahigh degree of softness to the touch.

Example 9b The procedure of Example 9 is repeated with the modificationthat isomeric hydroxy propyl methacrylate is employed in place ofhydroxy ethyl methacrylate.

Example 9c The procedure of Example 9a is repeated with the modificationthat a-cumene hydroxy peroxide is employed as the free-radical vinylpolymerization catalyst.

Example 10a 2-hydroxy ethyl methacrylate (50 parts) and Ti (30 parts)are ground in a pebble mill to a fine powder (Hegeman 7-8). Additional2-hydroxy ethyl methacrylate (50 parts) is added along with ethyleneglycol dimethacrylate (0.2 part), cobalt naphthenate a conventionalmetallic paint dryer or catalyst (0.1 part) and t-butyl peroctoate (0.4part). The resulting viscous syrup is painted onto a wooden boat hulland cured at 20 to 35 C. The resulting protective marine coating ischaracterized by its ability todiscourage 'barnacle and algae growth andcorrosion on prolonged underwater exposure.

Example 10b The procedure of Example 10a is repeated with themodification that the coating syrup is cast ontoa steel hull and curedat 100 C. in the absence of cobalt naphthenate.

Example 100 The procedure of Example 10a is repeated employing anisomeric mixture of hydroxy isopropyl methacrylate isomers in place ofthe hydroxy ethyl methacrylate.

Example 11a A solution comprised of 2-hydroxy ethyl methacrylate (100parts), ethylene glycol dimethacrylate (0.2 part), and t-butylperoctoate (0.4 part) is cast onto a neoprene rubber sheet and heated at70 C. for 1 hour. The resulting coated sheet is easily fabricated into abathing cap form having the aforementioned properties.

Example 11b A solution comprised of Z-hydroxy ethyl methacrylate (100parts), ethylene glycol dimethacrylate (0.2 part),

10 and t-butyl peroctoate (0.4 part) is cast onto a neoprene rubbersheet, covered by a second rubber sheet so as to exclude air, and heatedat C. for 1 hour. At the end of this time, both sheets are firmly bondedto one another by the intermediate polymeric layer.

Example 12a 2-hydroxy ethyl methacrylate parts) is stirred with 0.05part t-butyl peroctoate in a nitrogen atmosphere at a temperature of 40C. for 30 minutes. The resultant mixture is cooled to 25 C. and t-butylperoctoate added so as to make the total amount of t-butyl peroctoateadded in the system 0.15 part. Ethylene glycol dimethacrylate (0.1 part)is added at the same time. The casting solution is poured into moldsconforming to the desired shape of an intrauterine device of the typeshown in U.S. Pat. No. 3,200,815 and then cured at 70 C.

Example 12b The process of Example 12a is repeated, substituting 0.2part of 1,3-butylene glycol dimethacrylate as the crosslinking monomer.

Example 13a 2-hydroxy ethyl methacrylate (100 parts) is stirred withdistilled Water (50 parts) and tertiary butyl peroctoate (0.1 part), inan anaerobic atmosphere at a temperature of 40 C. for 20 minutes. Theresultant mixture is cooled to 25 C. and t-butyl peroctoate (005 part)added. A cross-linking monomer such as ethylene glycol dimethacrylate(0.2 part) is added at the same time as the catalyst. The castingsolution is dip-coated onto polyethylene intrauterine devices of thetype shown in US. Pat. 3,200,- 815 and cured at 70 C. for 1 hour. Suchproducts exhibiting a tacky or sticky surface are immersed in water todissolve all the unpolymerized remaining monomer material, therebyeffecting a smooth, non-tacky surface.

Example 13 b The process of Example 13a, repeated in the absence ofwater, resulted in a casting solution which upon curing formed asubstantially complete (99.5%) polymerized polymer product whichexhibited a smooth non-tacky surface.

Example 13c The process of Example 13b is repeated, substituting a mixedcatalyst consisting of 0.05 part t-butyl peroctoate and 0.1 partisopropyl percarbonate. Catalyst concentra tion is brought totheoretical by addition of isopropyl percarbonate.

Example 13d The procedure of Example 13b is repeated with themodification that BaSO (50 parts) is blended with the polymer systemprior to casting and final cure.

Example 14a Distilled 2-hydroxy ethyl methacrylate (100 g.) is stirredwith 0.1 g. tertiary butyl peroctoate in an anerobic atmosphere at 2570C. for 15-40 minutes. The resultant mixture is cooled to 25 C. andtertiary butyl peroctoate added so as to make the total concentration oftertiary butyl peroctoate in the system 0.2/ 100 grams of 2-hydroxyethyl methacrylate. Ethylene glycol dimethacrylate, in the concentrationof 0.2 g./100 g. of 2-hydroxy ethyl methacrylate is added at the sametime as the catalyst concentration is brought up to the theoreticalcontent. Micro silica of particle sizes 0.15-0.02 micron (commercialCab-O-Sil) is post added to the casting syrup to yield a prepolymersyrup of desired rheological properties for use as a denture liner basematerial. The casting syrup may be spread on a standard polymericacrylic denture base material and, after being impressed, polymerizedwith same in a single polymerizing process in a standard molding flaskunder standard conditions of time, temperature and pressure. In the caseof existing polymerized denture bases,

the casting syrup may be spread thereon and, after being impressed,polymerized under standard denture molding conditions, the latter beingdisclosed in US. Pat. No. 2,645,012. Casting syrups for in situpolymerization to form various articles having specific desiredproperties such as mechanical strength, high reversible fluid absorptionproperties, shape retention in fluid media and elasticity recovery afterdeformation are thereby formed.

Example 14b The process of Example 14a is followed, substituting hydroxypropyl methacrylate for the 2-hydroxy ethyl methacrylate monomer.

Example 14c The process of Example 14a is followed using isopropylpercarbonate as the catalyst and substituting 1,3-butylene glycoldimethacrylate as the cross-linking monomer.

Example 14d The process of Example 14a is followed with the exceptionthat an integral mouth guard impression is molded from an impression byuse of the said casting syrup. If desired, a reinforcing center elementof rubber may be dip-coated with the casting syrup so as to provideadditional rigidity.

Example 15a 2-hydroxy ethyl methacrylate (100 g.) is mixed with tertiarybutyl peroctoate in the quantity 0.15 g./ 100 g. methacrylate. Ethyleneglycol dimethacrylate, in the concentration of 0.20 g./100 g. 2-hydroxyethyl methacrylate is added along with 1 gm. of a foaming agent, sodiumbicarbonate. The mixture is heated to 70 C. and the resulting solid,friable polymeric foam is ground into fine powder of 80 mesh. Thepolymeric powder so formed is mixed with a natural anise flavor solutionand the resultant mixture is placed on a mechanical roller forapproximately 8 hours. The polymeric powder thus absorbs the flavor. Thesolution is then filtered and the residue dried at room temperatures.

Example 15b The process of the previous Example 15a is followed,substituting an oil of orchids perfume essence for the anise flavor.

Example 16 2-hydroxy ethyl methacrylate (100 g.) is mixed with tertiarybutyl peroctoate (0.20 g.). Ethylene glycol dimethacrylate (0.20 g.) isadded along with 4 g. of a foaming agent, sodium. bicarbonate. Themixture is heated to 70 C. and the resulting solid, friable polymericfoam is ground into fine powder of 80 mesh. The polymeric powder formedis mixed with a suflicient amount of phenoxymethyl penicillin antibioticdissolved in ethyl alcohol to provide for gradual release of 1,200,000units per gram, and the resultant mixture placed on a mechanical rolleruntil the polymeric powder has absorbed the desired concentration ofantibiotic. The solution is then filtered and the residue dried invacuo.

Example 17 Suitably purified 2-hydroxy ethyl methacrylate is stirredwith 0.15 g. of isopropyl percarbonate in an anaerobic atmosphere atambient temperature. Ethylene glycol dimethacrylate in the concentrationof 0.1 g./100 g. 2-hydroxy ethyl methacrylate is added. Heparin, ananti-coagulant, is added before casting. The solution is cast into atube or mold of known vessel thickness and diameter containing a Dacrontubularly shaped strengthening material so that in use, stitching of thevessel substitute to the vessel being repaired is facilitated. Thestrengthening material is completely encased by the casting solution.Insertion of an appropriately sized mandril into the mold yields anarterial vessel of the desired wall thickness. The shaped article isthen cured 30 minutes 12 at 40 C., removed from the mold, washed withwater and subsequently stored in an aqueous solution.

Example 18a 100 g. of 2-hydroxy ethyl methacrylate is mixed with 0.15 g.tertiary butyl peroctoate. 0.2 g. ethylene glycol dimethacrylate isadded, along with 1 g. of sodium bicarbonate. The mixture is heated to70 C. and the resulting polymer is disintegrated into pellet sizeparticles by grinding and shearing. The pellets are mixed in a 50-50mixture of glycerine and water for 8 hours to provide a non-migratoryhumectant action and dried. The resulting pellets are employed as atobacco smoke filter in a cigarette.

Example 18b The process of the preceding example is repeated with theexception that tobacco flavor is added to the glycerine-water mixture toimpart a tobacco flavor to the filtered smoke to replace the flavor lostby filtration of the tars and other combustion products which normallyimpart the tobacco flavor upon inhalation.

In a further embodiment, an alcoholic solution of menthol was employedas a flavoring agent along with the tobacco flavor. The alcoholicsolutions may be employed so as to result in amounts ranging from 1 topercent by weight of the hydrophilic polymer, although 10 percent ispreferred, particularly if glycerine is employed as the humectant.

Example 18c parts 2-hydroxy ethyl methacrylate is stirred with 0.05 parttertiary butyl peroctoate in a nitrogen atmosphere at a temperature of30 C. for 30 minutes. The resultant mixture is cooled to 25 C. andadditional peroctoate is added to make up a total of 0.15 part, 0.1 partethylene glycol dimethacrylate being added at the same time. The castingsolution is poured onto a plate in the form of a film and cured at 70 C.for 30 minutes to result in a chromatographic filter element capable ofabsorbing water soluble stain and color components such as Water-solublepigmented bodies of synthetic and natural color dyes and the like.

Example 19 100 g. 2-hydroxy ethyl methacrylate is mixed with 0.20 g.tertiary butyl peroctoate in an inert atmosphere and 0.20 g. ethyleneglycol dimethacrylate is added. Watersoluble catalyst is added to themixture before casting at 40 C. for 30 minutes to formv a catalytic bedsupport. The dried support, when Wet with water, is adapted to releasethe catalyst in an aqueous solution or wet gas stream to be catalyzed.

Example 20a 100 g. 2-hydroxy ethyl methacrylate is stirred with 0.15 g.isopropyl percarbonate in an anaerobic atmosphere at ambienttemperature. 0.1 g. ethylene glycol dimethacrylate is added. Beforecasting, a 2% aqueous solution of Merbromin is added as a generalantiseptic. The resulting solution is cast onto a Dacron mesh cloth inthe form of a film to result in a bandage form upon curing for 30minutes at 40 C. The dried bandage, upon being wetted by immersion inwater, or on contact with the lymphatic exudate of an open wound or withmucous membrane, gradually releases the antiseptic.

Example 20b A sheet or film in bandage form is made in accordance withExample 20a having a thickness range from about 5 mils to 1.5 mm. Inplace of the general antiseptic the topical antibiotic neomycin sulfateis added before casting in an amount of 5 mg. (equivalent to 3.5 mg.base) per gram of polymeric carrier. The resultant film is employed as atemporary covering for burns, it being found that the antibiotic loadingof the polymer in contact with flesh burns prevents the dreadedcomplication of pseudo- 13 monas injection and septicemia as well aslimiting fluid loss from the burn surface.

Example 21 The process of Example 12a is repeated, the casting solutionbeing poured into molds conforming to the shape of a contact lens buttonwhich, after cooling and drying, can be ground by conventional means toform toric contact lenses. by compensating for the volumetric increaseof about 18 percent resulting from wetting the lens after grinding, thegrinding operation can be performed accurately to give the desireddimensions.

Example 23 The process of Example 12a is repeated, the casting solutionbeing poured into molds conforming to the shape of the desiredprosthetic devices and body implants.

Example 24 Bristles adapted for use in tooth brushes, cleansing brushes,and the like may be prepared by the process described in Example 9. Ifadditional strength is desired for the bristles, they may be formed withan axial fiber of nylon or the like and dip-coated as described in theforegoing Example 14d, the reinforcing center element being of rubber,plastic or the like.

Example 25a 'The casting solution prepared in accordance with Example12a is employed as a base stock casting solution or syrup to which oilof peppermint, a flavoring agent, is added in an amount of 10 parts. Theflavored casting so lution is set aside and can be employed as desiredto form cast products in the form of shaped bodies or in powdered form.In a further embodiment, the flavoring agent is added along with themakeup catalyst.

Example 25b The casting solution of Example 13a is employed as a base orstock solution to which oil of orchids perfume essence (10 parts) isadded. The resulting perfume carrying stock solution is set aside forlater employment as a casting solution or syrup to form upon curing ashaped body in the form of an artificial flower decoration adapted foruse as a decorative package attachment for a perfume bottle.

Example 250 The casting syrup of Example 14a is prepared without theemployment of micro silica. In place of the latter, an alcoholicsolution of menthol (10 parts) is added to the casting syrup to yield amentholated prepolymer casting syrup.

Example 25d The casting syrups of Examples 12a, 13a and 14a are employedas base casting syrups to which a water-soluble stain and color, asynthetic color dye and a natural color dye, respectively are added tothe base preparations to form a stock solution for later casting orother use.

Example 25c The casting solution of Example 17 is prepared and in placeof the anti-coagulant heparin, the antibiotic phenoxymethyl penicillinof Example 16, dissolved in ethyl alcohol, is added in an amount toprovide for gradual release of 1,200,000 units per gram of castingsyrup. The

resulting casting syrup is set aside as a stock solution for latercasting or other use. The casting syrup and the resulting cast producteither in shaped or powdered form are employed as a pharmaceuticalcarrier for the antibiotic. The use of the casting Syrup or resultingshaped or powdered preparation has the advantage that it preventsdeterioration and loss of potency to which the antibiotic is subject inconventional pharmaceutical carriers, thereby extending the shelf lifeor expiration date of the antibiotic preparation. In addition, thehydrophilic polymer prepared in accordance with the present inventionhas the desirable characteristics, whether dry or solvent filled, ofpreventing the imbibition with microbial and fungal contaminants, suchas gram negative and gram positive microorganisms, yeast, molds andviruses. This characteristic is of particular importance in the presenceof contaminants, such as preventing contamination of penicillin withvarious yeast forms.

Example 26 Distilled 2-hydr0xy ethyl methacrylate (100 g.) is stirredwith 0.05 tertiary butyl peroctoate in an anaerobic atmosphere at 2570C. for 14-40 minutes. The resultant mixture is cooled to 25 C. andtertiary butyl peroctoate added so as to make the total concentration oftertiary butyl peroctoate in the system 0.15/100 grams of 2-hydroxyethyl methacrylate. Ethylene glycol dimethacrylate, in the concentrationof 0.15 g./ 100 g. of 2-hydroxy ethyl methacrylate is added at the sametime as the catalyst concentration is brought up to the theoreticalcontent. Oil of peppermint flavoring (11.10 parts) is also added to thecasting syrup to yield a flavored prepolymer syrup which is suitable forstoring. After curing and granulation, the flavor carrying granules areadded as a flavoring releasing component to chewing gum, gelatin andantacid tablets.

Example 27 Ninety grams of a stock casting syrup, made in accordancewith Example 14a, is added under stirring 0.15 g. tertiary butylperoctoate in an anaerobic atmosphere at 2S70 C. for 15-40 minutes, theamount of monomer employed being adjusted to result in g. final castingsyrup. The resultant mixture is cooled to 25 C. and tertiary butylperoctoate added so as to make the total concentration of tertiary butylperoctoate in the system 0.15/ grams of 2-hydroxy ethyl methacrylate.Ethylene glycol dimethacrylate, in the concentration of 0.15 g./100 ofZ-hydroxy ethyl methacrylate is added at the same time as the catalystconcentration is brought up to the theoretical content. Oil ofpeppermint (10 g.) is added to the casting syrup to form a flavoredstock solution.

Example 28 The casting syrup of Example 14a is employed as a basesolution to which is added ethynodiol diacetate as the progestagencomponent plus mestranol as the estrogen component in an amountsuflicient to provide a timed daily release time of 10 to 1 parts byweight, respectively, when the casting syrup is prepared in the form ofa shaped body or in powdered form. The resulting preparation is used asa body implant, or tablet for oral administration for contraception orin other therapy for fertility regulation or disturbance. One advantageof the use of the instant hydrophilic polymers as pharmaceuticalcarriers is that it permits a desired slow release or timed release ofthe active component. The release time is adjusted readily by the amountof cross-link agent employed, the surface to volume ratio of the formedplastic, and the concentration or concentration gradient of thebiologically active substance so incorporated. Release rate is increasedby inclusion of solvent in the casting solution.

Example 29 Purified Z-hydroxy ethyl methacrylate (100 g.) is mixed with0.2 g. of ethylene glycol dimethacrylate and 1 g. of

1 benzoyl peroxide. The monomer solution is sprayed via a nozzle whichforms fine droplets into a chamber containing nitrogen at a temperatureof 150 C. After spraying of the monomer was concluded, 36 g. of polymerbeads suitable for impregnation by flavors or scents was recovered fromthe floor of the chamber.

Example 30 Purified 2-hydroxy ethyl methacrylate (100 g.) is mixed with15 g. of ethylene glycol dimethacrylate, g. of orange oil and 0.3 g. oftertiary butyl peroctoate. The solution is poured into a 250 ml.polypropylene beaker which is placed in an oven under a nitrogenatmosphere at 80 C. for 3 hours to effect polymerization. The castcylinder so obtained is friable, and can easily be comminuted to apowder which rapidly releases the orange oil in contact with hot water.

Example 31 In 3 cc. of Z-hydroxy ethyl methacrylate containing .2% ofethylene glycol dimethacrylate and 0.15% tertiary butyl peroctoate wasdissolved 100 milligrams of norethandrolone (Nilevar). The solution wascast in the form of a cylinder 1 cm. 3 cm. and was polymerized at 80 C.for 3 hours in a nitrogen atmosphere. After removing from the mold, acylinder suitable for in vivo implantation to provide prolonged releaseof the norethandrolone (Nilevar) was obtained for use in animalhusbandry.

Example 32 Raw cotton suture thread is immersed in the casting syrup ofExample 14a with thickening agent omitted and is passed through apolymerization zone having a nitrogen atmosphere maintained at 100 C.'Residue time in the zone is held at 1 /2 hours. The coated, impregnatedsuture so obtained is soaked in an alcoholic solution offluorothiouracil and penicillin, and is then dried. The surgical suturethus obtained is beneficial in preventing spread of infection andspurious cell migration along suture lines during post-operativehealing.

Example 33a A rubber Foley catheter is immersed in the casting syrup ofExample 14a with the thickening agent omitted, and then is removed andsubjected to a temperature of 80 C. in an inert atmosphere to effectpolymerization of the coating thus applied. The coated catheter is thenimmersed in an aqueous solution of neomycin sulfate and is then dried toprovide a catheter effective in preventing infections when used in theurinary tract.

Example 33b A tube made according to Example 23 which is 5 cm. in lengthwith an outer diameter of 3 mm. and a wall thickness of 0.8 mm. isfitted at each end with a Teflon felt collar adhered thereto by Silastic(silicone) adhesive. The device is employed to join the severed ends ofa ureter by suturing the ends thereof to the Teflon collars. Segmentedureter replacements in the dog have functioned satisfactorily for over 6months and upon sacrifice no encrustations were observed within thelumen of the polymer.

Example 330 The process of Example 33a is employed to cast tubes ofvarious sizes for use as vessel grafts and substitutes, common ducts,urethral replacement segments and lung tracheal segments. It has beenfound that Venus tubes deep-coated with ethyl alcohol solutions of thepolymer preparations of Example 33a can be placed in the inferior andsuperior of the vena cava for extended periods whereas uncoated plastictubes ordinarily clot in the venous stream within minutes. Suchdip-coating can be applied to thrombogenic plastics to body insertmaterials and heart valve component fabrication. The polymer solution ofExample 33a in aqueous ethyl alcohol also is adapted to be cast in situas a film on moist internal body surfaces as by brush coating on theabraded surfaces of bowel to deter adhesion formation.

Example 34 100 g. of casting syrup of Example 33a was added to threetimes its volume of water with vigorous agitation. The white precipitateso obtained was isolated by filtration and dried to yield 9.0 g. ofpolymer showing an intrinsic viscosity of 1.03 when dissolved inabsolute methanol. The polymer, as dissolved in methanol, is suitablefor the formation of hydrophilic coatings and films by spray coating,dip coating, casting and the like. The resulting cast polymer exhibitedcontrolled hydrophilic properties being incapable of absorbing more than30% water when equilibrated in aqueous medium.

Example 35 The solution of Example 17 is used to bond heparin throughabsorption of benzalkonium chloride as reported in Gotts technique (J.Surg. Research, vol. 6, p. 274, 1966).

Shaped articles of the hydrophilic polymer solution of Example 33a alsocan be employed for ion transfer in hemodialysis for the incorporationof the hemostatic agent thrombin and as carriers for estrogens, nitrogenmustard, parathormone, the transport of edema fluid and for the exportof oxygen saturated solutions to a blood-plastic interface in artifiicallung applications. Pellets or discs of the instant polymeric materialcan be soaked in oral antiseptic solutions and can be employed in theoral cavity, particularly in the buccal pouch or in the sublingualcavity for the slow release of the oral anti-septic as a breathsweetener.

Example 36a Into a flask equipped an agitator and a heating mantle wascharged 1000 grams of silicone oil; 100 grams of Z-hydroxy ethylmethacrylate and 0.33 gram of isopropyl percarbonate. The flask wasplaced under a nitrogen atmosphere and the contents were rapidlyagitated and heated to 100 C. After 15 minutes at 100 C., the polymerslurry obtained was filtered hot to isolate the polymer. The polymerpowder was reslurried in 300 ml. of xylene, filtered and dried. A 98%yield of 2 to 5,11. particle size powder was obtained. The powder wasemployed in the injection molding and extrusion of shaped articles.Additionally, the powder was dissolved in ethanol to form solutions forcasting hydrophilic polymer films.

Example 36b Example 36a was repeated using mineral oil in place of thesilicone oil. The amount of 2-hydroxy ethyl methacrylate was increasedfrom 100 g. to 200 g. and the quantity of isopropyl percarbonate wasincreased from 0.33 to 0.66 g. A 98% yield of polymer beads ranging indiameter from 2 to 5 microns was obtained.

Example 36c Example 36a was repeated using xylene in place of thesilicone oil. The amount of 2-hydroxy ethyl methacrylate was increasedfrom 100 g. to 300 g. and the quantity of isopropyl percarbonate wasincreased to 0.99 g. An yield of polymer beads was obtained.

Example 37 Poly-(2-hydroxy ethyl methacrylate) 30 g., prepared inaccordance with Example 36a, was dissolved in 70 ml. of methanol. To thesolution was added 4.0 g. of peppermint oil. The viscous solution wascoated on an impervious plate and allowed to dry to form a film 1.0 milthick. The dry film was stripped from the plate and was ground to formminute platelets suitable for incorporation in food products, chewinggum and toothpaste to provide prolonged release of the peppermint flavoron contact of the product with an aqueous medium. When 17 equilibratedin aqueous medium the platelets were characterized by controlledhydrophilicity, being incapable of absorbing in excess of 30% by weightof water.

Example 38 Example 37 was repeated with the following flavoringmaterials:

anethole citral ethyl propionate ethyl acetate acetaldehyde biacetylmenthol Spearmint expressed orange oil tobacco extract Powders wereobtained for incorporation in and on articles appropriately suited forthe particular flavor incorporated in the powder to provide forcontrolled release of the flavoring material upon and during wetting ofthe powder.

Example 39 Poly-(2-hydroxy ethyl methacrylate), 50 grams, prepared inaccordance with Example 36a, was dissolved in 50 ml. of methanol to forma viscous dope; menthol, 12.5 g., was dispersed in the dope which wasthen forced through a spinaret to form fine filaments which werepermitted to dry and thereafter were chopped to a fine powder for use inflavored products.

Example 40 To 100 ml. of the ethanolic solution of Example 36a was added2.5 ml. of biacetyl. The solution was sprayed via a nozzle into a heatedchamber having a high velocity air flow to effect spray drying of thesolution. Particles ranging in size from 2-15 microns in diameter wererecovered from the spray drying apparatus. These particles were suitablefor incorporation in food products to provide controlled release of thebiacetyl flavor, and to prevent oxidation, deterioration orvolatilization of the flavor during storage.

Example 41 3.6 grams of the powder of Example 36a is impregnated with.008 g. of N,N-dimethyl aniline by wetting the powder with an acetonesolution of dimethyl aniline and allowing the mixture to dry.

In a separate container, 9.9 g. of Z-hydroxyethyl methacrylate is mixedwith 0.0214 gram of ethylene glycol dimethacrylate and 0.05 gram ofbenzoyl peroxide.

3.6 g. of the impregnated powder, when mixed with 9.9 g. of theformulated hydroxyethyl methacrylate mixture formed a paste mixturewhich cured within 30 minutes with no applied heat to form a hydrophilicplastic article.

This mixture before cure was used to line a denture without thenecessity of using a molding flask and without applied heat and pressureas employed in Example 14a. The mixture before cure was applied to astandard acrylic denture base material, and with the aid of a barrierfilm or bag, the denture was placed in the mouth to form the impressionof the gum and was permitted to cure in the mouth. A total curing timeof 10 minutes was used, with minutes curing time taking place in themouth. The denture liner thus applied exhibited the properties of thedenture liner of Example 14a.

Prepared ratios of liquid monomer to powder are from about 2 to 1 toabout 4 to 1. Catalyst and activator amounts can be varied to adjust thecuring time and exothermic temperatures. As will be apparent, theinstant process and formulation enables chair-side preparation and cureof the denture liner directly on the gum of the patient to achieve anexact profile and fit.

Example 42 Discs of hydrophilic polymer, prepared as shaped articlesfrom the solution of Example 34, measuring A inch in diameter and 0.5mm. in thickness were saturated with an antibiotic solution oflincomycin hydrochloride monohydrate (Lincocin) and tested againststandard staphylococcic strains on agar plates. The zones of inhibitionwere compared with standardized 1 mg. discs obtained from themanufacturer. Multiple transfers of the hydrophilic polymer also weremade on blood agar to determine how long the elution of the antibioticfrom the gel would take place.

It was observed that inhibition of the standard bacterial strainoccurred up to 22 days. Comparable paper discs with the same antibioticexhibited zones of inhibition only for 48 hours. In some cases 6transfers of the discs, each to a fresh blood agar plate, were carriedout. From the results it was apparent that the elution of the agent fromthe hydrophilic polymer disc is a gradual process and extends over asignificant period of time. Moreover, it appears that it is possible toheavily saturate the gel with the desired agent.

Example 43 Shaped articles made in accordance with Example 23 in theform of irregular cylinders and blocks were implanted within the rightatrial chamber of the dog in order to determine the blood vascularcompatibility of the hydrophilic polymer. Upon sacrifice of the dogs,after one month, it was apparent that the hydrophilic polymer did notfoster thrombosis and that the only clot observed was at the point ofattachment of the hydrophilic polymer article to the atrial wall.

In an in vitro study, glass test tubes coated with methyl alcoholsolutions of the hydrophilic polymer made in accordance with Example 37,were filled with canine blood and clotting times were observed. It wasnoted that as against the controlled clotting times of 6 minutes thehydrophilic polymer coated tubes clotted at an average of 3.5 hours,thereby evidencing that the hydrophilic polymer discouraged surfacethrombogenesis.

'Additional desired vascular substitute properties exhibited by suchimplants include wettability, lubricity, conductivity, distensibilityand the capability of absorbing and transporting ions of organic andinorganic compounds at high concentration and high rates of transferincluding chlorine, sodium, potassium, and phosphate ions.

Example 43a A glass plate for use as a vehicle windshield, window ormirror was coated with a methyl alcohol solution of the hydrophilicpolymer made in accordance with Example 37. The resulting coating (0.005inch thick) was lighttransmitting and optically clear, adherent, and didnot fog upon exposure to hot moist air. Similarly, a plastic plate ofmethyl methacrylate for use as an aircraft windshield was so coated.

Example 43b The procedure of Example 43a was followed to coat an opticalelement in the form of a camera lens having a reflection-reducing filmof magnesium fluoride thereon to form a light-transmitting, opticallyclear, reflectionreducing, non-fogging optical element.

Example 44 Io the ethanolic solution of Example 36 was added theantibiotic chloramphenicol and the resulting solution was employed tocoat a nylon suture.

Example 45 To the ethanolic solution of Example 36a was added analcoholic solution of Mercurochrome. The resulting solution was appliedby spraying as a wound dressing.

Example 46 3.6 grams of powder of Example 36a is impregnated withMercurochrome from an acetone solution. The powder is then dried anddusted on a wound as a dressing to provide antiseptic action.

The foregoing examples are directed primarily to the in situ addition ofdyes, pigments, thickening agents, resins, medicinally-activesubstances, bacteriocides, antivirals, fungicides, strengtheningmaterials, antiseptics, catalyzers, nutrient media, anti-coagulants,steroids and the like during the casting syrup preparation after theinitial step in which the Water-soluble uncrosslinked homopolymer of thepolyhydroxy ethyl methacrylate or the like is formed and preferably atthe stage of addition of the makeup catalyst. However, certain additivecomponents, particularly pigments, thickening agents, resins and thelike can be added directly to the initial monomer or during the initialpolymerization.

What is claimed is:

1. A denture having adhered to the buccal surface 15 1 thereof as adenture liner, a cured, cross-linked polymer of a water-solublepolymerizable monoester of an olefinic acid having one substitutedfunctional group.

2. A denture according to claim 1 wherein the polymer is a polymer ofhydroxyalkyl acrylate or methacrylate.

3. A denture according to claim 2 wherein the monoester is hydroxyethylmethacrylate.

References Cited UNITED STATES PATENTS 13,488,846 1/1970 Cornell 3283,307,260 3/1967 Allen 322 ROBERT PESHOCK, Primary Examiner

